The present invention is directed to ink compositions and to processes for the use thereof. More specifically, the present invention is directed to compositions suitable for use in ink jet printing processes. One embodiment of the present invention is directed to an ink composition which comprises (a) water, (b) a colorant, and (c) a material of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20.
Ink jet printing systems generally are of two types: continuous stream and drop-on-demand. In continuous stream ink jet systems, ink is emitted in a continuous stream under pressure through at least one orifice or nozzle. The stream is perturbed, causing it to break up into droplets at a fixed distance from the orifice. At the break-up point, the droplets are charged in accordance with digital data signals and passed through an electrostatic field which adjusts the trajectory of each droplet in order to direct it to a gutter for recirculation or a specific location on a recording medium. In drop-on-demand systems, a droplet is expelled from an orifice directly to a position on a recording medium in accordance with digital data signals. A droplet is not formed or expelled unless it is to be placed on the recording medium.
Since drop-on-demand systems require no ink recovery, charging, or deflection, the system is much simpler than the continuous stream type. There are two types of drop-on-demand ink jet systems. One type of drop-on-demand system has as its major components an ink filled channel or passageway having a nozzle on one end and a piezoelectric transducer near the other end to produce pressure pulses. The relatively large size of the transducer prevents close spacing of the nozzles, and physical limitations of the transducer result in low ink drop velocity. Low drop velocity seriously diminishes tolerances for drop velocity variation and directionality, thus impacting the system's ability to produce high quality copies. Drop-on-demand systems which use piezoelectric devices to expel the droplets also suffer the disadvantage of a slow printing speed.
The other type of drop-on-demand system is known as thermal ink jet, or bubble jet, and produces high velocity droplets and allows very close spacing of nozzles. The major components of this type of drop-on-demand system are an ink filled channel having a nozzle on one end and a heat generating resistor near the nozzle. Printing signals representing digital information originate an electric current pulse in a resistive layer within each ink passageway near the orifice or nozzle, causing the ink in the immediate vicinity to evaporate almost instantaneously and create a bubble. The ink at the orifice is forced out as a propelled droplet as the bubble expands. When the hydrodynamic motion of the ink stops, the process is ready to start all over again. With the introduction of a droplet ejection system based upon thermally generated bubbles, commonly referred to as the "bubble jet" system, the drop-on-demand ink jet printers provide simpler, lower cost devices than their continuous stream counterparts, and yet have substantially the same high speed printing capability.
The operating sequence of the bubble jet system begins with a current pulse through the resistive layer in the ink filled channel, the resistive layer being in close proximity to the orifice or nozzle for that channel. Heat is transferred from the resistor to the ink. The ink becomes superheated far above its normal boiling point, and for water based ink, finally reaches the critical temperature for bubble formation or nucleation of around 280.degree. C. Once nucleated, the bubble or water vapor thermally isolates the ink from the heater and no further heat can be applied to the ink. This bubble expands until all the heat stored in the ink in excess of the normal boiling point diffuses away or is used to convert liquid to vapor, which removes heat due to heat of vaporization. The expansion of the bubble forces a droplet of ink out of the nozzle, and once the excess heat is removed, the bubble collapses on the resistor. At this point, the resistor is no longer being heated because the current pulse has passed and, concurrently with the bubble collapse, the droplet is propelled at a high rate of speed in a direction towards a recording medium. The resistive layer encounters a severe cavitational force by the collapse of the bubble, which tends to erode it. Subsequently, the ink channel refills by capillary action. This entire bubble formation and collapse sequence occurs in about 10 microseconds. The channel can be refired after 100 to 500 microseconds minimum dwell time to enable the channel to be refilled and to enable the dynamic refilling factors to become somewhat dampened. Thermal ink jet processes are well known and are described in, for example, U.S. Pat. No. 4,601,777, U.S. Pat. No. 4,251,824, U.S. Pat. No. 4,410,899, U.S. Pat. No. 4,412,224, and U.S. Pat. No. 4,532,530, the disclosures of each of which are totally incorporated herein by reference.
U.S. Pat. No. 5,019,166 (Schwarz), the disclosure of which is totally incorporated herein by reference, discloses a thermal ink jet printing composition comprising a dye, a liquid medium, and a surfactant selected from the group consisting of polyoxyalkylated ethers, anionic bitail fluorothio alkyls, alkyl aryl sulfonates, alkyl amine quaternary salts, and mixtures thereof. Also disclosed is a process for generating images which comprises causing the ink compositions disclosed herein to be ejected from a thermal ink jet printer in imagewise fashion onto a substrate.
U.S. Pat. No. 5,401,303 (Stoffel et al.), the disclosure of which is totally incorporated herein by reference, discloses a process wherein the halo effect seen at the interface between a first ink, exhibiting sharp edge acuity, and a second ink, having low surface energy, is addressed by adding certain fluorocarbon compounds to the first ink. Edge acuity of the first ink is maintained.
U.S. Pat. No. 5,540,765 (Gundlach et al.), the disclosure of which is totally incorporated herein by reference, discloses a thermal ink jet printing composition which contains a surfactant comprising an alkylsulfoxide having an alkyl group of 4 to 6 carbon atoms. Preferably, the composition contains a betaine zwitterionic base and dibutylsulfoxide.
U.S. Pat. No. 5,531,815 (Gundlach et al.), the disclosure of which is totally incorporated herein by reference, discloses a thermal ink jet printing composition contains a betaine zwitterionic base and a quasisurfactant penetrant.
U.S. Pat. No. 5,389,133 (Gundlach et al.), the disclosure of which is totally incorporated herein by reference, discloses a process for preparing an aqueous ink composition which comprises adjusting the pH of the ink with phosphorous acid or phosphite salts. Also disclosed are ink compositions prepared by this process. In certain preferred embodiments, the ink compositions can also contain betaine, sulfolane, dimethyl sulfoxide, or N,N'-bis(3-aminopropyl)-1,2-ethylenediamine, as well as mixtures thereof. In other preferred embodiments, the ink composition comprises an organic component selected from the group consisting of sulfolane, dimethyl sulfoxide, and mixtures thereof, and anions selected from the group consisting of phosphite, hypophosphite, phosphate, polyphosphate, sulfate, hexafluorophosphate, glycolate, acetate, ethylenediaminetetraacetate, formate, borate, sulfite, sulfamate, and mixtures thereof.
Copending application U.S. Ser. No. 08/961,335 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Richard L. Colt, and Edward J. Radigan, Jr., now U.S. Pat. No. 5,772,744, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, a colorant, betaine, a tertiary amine, and a material of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ !, wherein n is an integer of from about 8 to about 20 and B is a cation. In one specific embodiment, n is 10 and B is (HO--CH.sub.2 CH.sub.2).sub.2 NH.sub.3.sup.+. In another specific embodiment, the tertiary amine is 1-methylimidazole. In yet another specific embodiment of the present invention, the colorant is an anionic dye with carboxylate groups, sulfonate groups, or both carboxylate and sulfonate groups. Also disclosed is a process for preparing the aforementioned ink composition wherein a liquid containing the material of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ ! is subjected to centrifugation. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/961,435, filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, Cheryl A. Hanzlik, Kathy-Jo Brodsky, Richard L. Colt, Aileen M. Montes, and Edward J. Radigan, Jr., now U.S. Pat. No. 5,772,743 the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises (a) water, (b) a colorant, (c) a fluorinated material selected from: (1) those of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ !, wherein n is an integer of from about 8 to about 20 and B is a cation, (2) those of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20, and (3) mixtures thereof, and (d) a monomeric compound having at least two carboxylic acid functional groups. Also disclosed is a process for preparing said ink composition which comprises (i) admixing the ink ingredients, and (ii) subjecting the mixture thus formed to ultrasonification, thereby reducing the average particle diameter of liposomes of the fluorinated material in the ink. Further disclosed is a process which entails (i) incorporating into an ink jet printing apparatus the aforementioned ink composition, and (ii) causing droplets of the ink composition to be ejected in an imagewise pattern onto a substrate. In a preferred embodiment, the printing apparatus employs a thermal ink jet process wherein the ink in the nozzles is selectively heated in an imagewise pattern, thereby causing droplets of the ink to be ejected in imagewise pattern.
Copending application U.S. Ser. No. 08/961,461 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach and Walter F. Wafler, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, a colorant, a nonionic surfactant, and a fluorinated material selected from the group consisting of (a) those of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ !, wherein n is an integer is an integer of from about 8 to about 20 and B is a cation, and (b) those of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/961,637 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, Cheryl A. Hanzlik, Kathy-Jo Brodsky, Richard L. Colt, and Aileen M. Montes, now U.S. Pat. No. 5,769,929, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, an anionic dye having at least one anionic functional group and having a cationic counterion associated with each anionic functional group, and a material of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ !, wherein n is an integer of from about 8 to about 20 and B is a cation, said ink composition containing alkali metal cations in an amount of no more than about 1.times.10.sup.-3 moles per liter. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/961,173 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, Richard L. Colt, and Rachael L. McGrath, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, a colorant, a bisquaternary ammonium compound, and a material of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/961,393 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Richard L. Colt, Luis A. Sanchez, and Danielle Avolio, now U.S. Pat No. 5,766,326, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, a colorant, 1,4-diazabicyclo2.2.2!octane, and a fluorinated material selected from the group consisting of (a) those of the formula (F.sub.2n+1 C.sub.n CH.sub.2 S).sub.2 (CH.sub.3)C--CH.sub.2 CH.sub.2 COO.sup.- !B.sup.+ !, wherein n is an integer of from about 8 to about 20 and B is a cation, and (b) those of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20. Also disclosed are processes for preparing the aforementioned ink and ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/960,991, filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, and Richard L. Colt, now U.S. Pat. No. 5,776,230, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises water, a dye selected from the group consisting of Direct Blue 199, Direct Yellow 132, Acid Yellow 17, Reactive Red 180, Acid Red 52, and mixtures thereof, and a material of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20, wherein the ink is substantially free of imidazole. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/960,792 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, Richard L. Colt, and Danielle Avolio, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises (a) water, (b) a colorant selected from the group consisting of Acid Yellow 23, Acid Yellow 17, Reactive Red 180, Direct Blue 199, Acid Blue 9, and mixtures thereof, (c) imidazole, (d) an additive selected from the group consisting of betaine, polyethylene oxide, and mixtures thereof, and (e) a material of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20. Also disclosed are ink jet printing processes employing the aforementioned ink.
Copending application U.S. Ser. No. 08/961,334 filed concurrently herewith, entitled "Improved Ink Compositions for Thermal Ink Jet Printing," with the named inventors Kurt B. Gundlach, Luis A. Sanchez, Danielle Avolio, Maura A. Sweeney, and Richard L. Colt, now U.S. Pat. No. 5,766,325, the disclosure of which is totally incorporated herein by reference, discloses an ink composition which comprises (1) water, (2) a colorant, (3) a material of the formula (F.sub.3 C(F.sub.2 C).sub.n CH.dbd.CHCH.sub.2 OCH(OH)CH.sub.2).sub.2 NCH.sub.2 COO.sup.- !X.sup.+ !, wherein X is a cation and n is an integer of from about 3 to about 20, (4) a polymer selected from the group consisting of (a) tetrafunctional block copolymers derived from the addition of propylene oxide and ethylene oxide to ethylenediamine; (b) polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymers; (c) polypropylene oxide-polyethylene oxide-polypropylene oxide triblock copolymers; (d) ethoxylated 2-naphthol polymers; and (e) mixtures thereof; and (5) an additive selected from the group consisting of (i) diethylene glycol; (ii) glycerol; (iii) trimethylol propane; (iv) urea; (v) n-methyl pyrrolidone; (vi) sulfolane; (vii) 1,4 diazabicyclo2.2.2!octane; (viii) cyclohexylpyrrolidone; and (ix) mixtures thereof. Also disclosed are ink jet printing processes employing the aforementioned ink.
While known compositions and processes are suitable for their intended purposes, a need remains for improved ink compositions suitable for use in thermal ink jet printing processes. In addition, a need remains for ink compositions which exhibit improved shelf stability at pH values below 9.0. Further, a need remains for ink compositions which exhibit improved viscosity stability with respect to pH and temperature. Additionally, a need remains for ink compositions with reduced viscosity. There is also a need for ink compositions with improved jetting characteristics. In addition, there is a need for ink compositions which can be prepared rapidly. Further, there is a need for ink compositions which exhibit improved filtration characteristics. Additionally, there is a need for ink compositions that exhibit reduced intercolor bleed when inks of different colors are printed in adjacent areas. A need further remains for ink compositions for which a wide variety of colorants are suitable and compatible with the ink ingredients. In addition, a need remains for ink compositions with surface tension values of greater than about 25 dynes per centimeter. Further, a need remains for ink compositions with improved wetting characteristics. Additionally, a need remains for ink compositions which exhibit improved recoverability characteristics in ink jet printers. There is also a need for ink compositions which enable a wide color gamut. In addition, there is a need for ink compositions which enable prints with reduced curl when the inks are printed onto substrates such as paper. Further, there is a need for ink compositions which enable prints with improved transparency transmission and improved wetting characteristics when the inks are printed onto transparent substrates. Additionally, there is a need for ink compositions with improved latency characteristics. A need additionally remains for ink compositions which exhibit reduced showthrough when printed on paper. Further, a need remains for ink compositions which are suitable for printing on a wide variety of substrates. In addition, a need remains for ink compositions which remain homogeneous over extended periods of time. Further, a need remains for ink compositions which exhibit further improvements in intercolor bleed characteristics when prints generated therewith are subjected to drying-assisting processes such as heating, microwave drying, or the like.